Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
8 Months Ended
Dec. 31, 2019
Mar. 13, 2020
Jun. 30, 2019
Entity Registrant Name LGL Systems Acquisition Corp.    
Entity Central Index Key 0001777946    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Document Type 10-K    
Document Period End Date Dec. 31, 2019    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2019    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Shell Company true    
Entity File Number 001-39125    
Entity Interactive Data Current Yes    
Entity Incorporation State Country Code DE    
Entity Public Float     $ 0
Class A Common Stock [Member]      
Entity Common Stock, Shares Outstanding   17,250,000  
Class B Common Stock [Member]      
Entity Common Stock, Shares Outstanding   4,312,500